耕作措施与秸秆还田对小麦－玉米轮作体系土壤质量的影响

摘要

To determine reasonable cultivation mode for dryland farming practice ,the effects of tillage and residue management on soil properties were compared in a winter wheat-summer maize cropping system .This experiment was con-ducted during the seven consecutive years of 2002—2009 in Guanzhong plain of Shaanxi province .Treatments included 8 factorial combinations of four tillage practices :subsoiling tillage (ST ) ,rotary tillage (RT ) ,no tillage (NT ) ,conven-tional tillage (CT ) ,and maize residue (with or without ) management .Soil samples were collected after wheat harvest in June 2009 and maize harvest in October 2009 .The highest soil bulk density in the 0~10 cm soil layer after maize har-vest was observed under NT ,followed by that for CT and RT ,and the lowest value was observed under ST .Compared with maize residue removed treatment (-r ) ,soil bulk density in the 0~10 cm soil layer under residue retained treat-ment (+r) was significantly decreased by 2 .33% .Multivariate analyses were used to select appropriate soil quality in-dicators .The results showed that the three soil property groups (i .e .soil nutrient group ,soil organic matter and environ-ment group ,enzymatic activity group ) responded more to tillage practice than to residue management .CT resulted in the poorest soil quality in both seasons .The residual effects of ST and RT on soil quality were found in maize season .Addi-tionally ,scores for soil organic matter and nutrient factor under ST and RT were higher in both seasons ,but the opposite occurred in NT .Based on soil quality ,crop yield and economic benefit ,the practice of the subsoiling rotary tillage plus residue retained to wheat combined with no tillage plus high stubble mulching to maize can be promoted in such dryland regions .%通过在陕西关中平原地区连续7年的田间定位试验，运用多元方差分析及因子分析法比较评价了冬小麦－夏玉米轮作体系下4种耕作措施（深松、旋耕、免耕、传统耕作）及2种秸秆管理措施（玉米秸秆还田、不还田）对土壤质量的影响。结果表明：玉米收获后0～20 cm土壤容重免耕处理最大，旋耕、翻耕处理次之，深松处理最小；秸秆还田0～10 cm土壤容重较不还田处理降低2．33％，达显著水平。小麦、玉米收获后0～20 cm土壤养分组、有机质环境组及酶活性组指标变量受不同耕作措施的影响均大于受秸秆管理措施的影响。传统耕作两季土壤质量均最差。深松、旋耕有一定后效，且有机质养分因子得分较高，免耕则相反。综合土壤质量、作物产量及经济效益，玉米秸秆还田／深松／旋耕／播种小麦－小麦秸秆高留茬／免耕／播种玉米模式适宜在该区推广。